FIBRONECTIN AND CIRCULATING IMMUNE-COMPLEXES IN BEHCETS-DISEASE

Being a high-molecular-weight adhesive glycoprotein, fibronectin (Fn) is suggested to be a component of immune complexes and may participate in the clearance of immune complexes. In Behcet's disease (BD), a mul tisystem disorder of unknown etiology, immune complexes have been show n to be deposited in affected tissue during disease activity, suggesti ng an immune mechanism. This study investigates the relationship betwe en Fn and circulating immune complexes (CIC) and evaluates the changes in the levels of Fn and CIC along with disease activity. In 63 patien ts (31 active, 32 inactive) with BD, plasma Fn and serum CIC, C-reacti ve protein (CRP), erythrocyte sedimentation rate (ESR) and the third a nd fourth components of the complement system (C3, C4) were studied. T he mean ESR, CRP, C3 and C4 levels of active BD patients were found to be significantly higher than those of the inactive BD patient group. Although the mean Fn and CIC levels of BD patients were not significan tly different from those of the healthy control group, Fn and CIC valu es of active BD patients were significantly lower than in the inactive group. Moreover, no significant correlation was observed among Fn lev els and ESR, CRP, C3, C4 and CIC levels in BD patients. The result of this study suggest that the variation in Fn concentration is independe nt of the acute-phase response. The lack of relationship between the C IC and Fn concentrations indicates that IC deposition in the vessel wa ll is independent of the CIC levels. In order to determine the exact r oles of Fn and IC, further studies in tissue specimens are required.